In examples, aircraft are designed to meet performance targets at maximum takeoff weight including takeoff field length and climb time or climb distance to a desired aircraft cruise altitude. Operation at less than maximum takeoff weight allows for a reduction of both takeoff and climb thrust from maximum ratings. Reducing takeoff and/or climb thrust from maximum ratings may be beneficial to engine life.
Time between engine refurbishments and cost of refurbishment are directly related to how an engine is operated. The key drivers are stage length, engine cycles per year, and how hard the engine is used, i.e., shaft speeds and core temperatures during takeoff and climb flight phases in addition to adverse environmental factors.
Reducing engine thrust during takeoff and climb flight phases may reduce engine core temperatures. In examples, the highest core temperature measured in an engine is turbine gas temperature, which may be measured by thermocouples or other temperature sensors in the low pressure turbine nozzle guide vanes. High pressure turbine blades achieve some of the highest temperatures in an engine and consequently are typically damaged by oxidation/burning and erosion. Allowing for reduced thrust during takeoff and climb flight phases reduces turbine gas temperature, thus reducing engine damage and extending engine life.
It is with respect to these and other considerations that the disclosure made herein is presented.